WO2005081294A1 - Exposure device, liquid treating method, exposure method, and device production method - Google Patents

Abstract

An exposure device capable of properly discharging collected liquid; a liquid treating method; an exposure method using the liquid treating method; and a device production method using the exposure device. The exposure device (EX) is a liquid immersion type exposure device for exposing to light a substrate (P) through a liquid (W) fed onto the substrate, having two collection tanks (41, 42) for collecting the liquid (W). A control device (CS) controls valves (45, 46) in synchronism with the operation of the exposure device (EX) to switch the collection tanks (41, 42) and to discharge the liquid (W) stored in that collection tank of the collection tanks (41, 42) which is not in communication with the collection nozzle (36) in synchronism with the operation of the exposure device.

Description

 Specification

 Exposure apparatus, liquid processing method, exposure method, and device manufacturing method

 Technical field

 The present invention uses a liquid immersion type exposure apparatus that irradiates exposure light onto a substrate via a liquid, a liquid processing method for processing a liquid used in the liquid immersion type exposure apparatus, and the liquid processing method. The present invention relates to an exposure method and a device manufacturing method using the exposure apparatus.

 This application claims the priority of Japanese Patent Application No. 2004-44804 filed on Feb. 20, 2004, the contents of which are incorporated herein by reference.

 Background art

 Devices such as semiconductor elements, liquid crystal display elements, imaging devices (CCD (charge coupled device), etc.) and thin-film magnetic heads use a pattern formed on a mask as a photosensitive substrate (a semiconductor wafer or glass plate coated with a resist). Etc.), and is manufactured by a so-called photography method. The exposure apparatus used in the photolithography process has a mask stage for supporting a mask, and a substrate stage for supporting a photosensitive substrate. The mask stage and the substrate stage are sequentially moved to project a pattern of the mask onto a projection optical system. This is a device for transferring images to a substrate via a.

 [0003] In recent years, in order to cope with higher integration of patterns formed on a device, it is desired to further increase the resolution of a projection optical system. The resolution of the projection optical system increases as the wavelength of the exposure light used decreases and as the numerical aperture of the projection optical system increases. For this reason, the wavelength of the exposure light used in the exposure apparatus is becoming shorter year by year, and the numerical aperture of the projection optical system is also increasing. Currently, the mainstream exposure apparatus is equipped with a KrF excimer laser (wavelength: 248 nm) as a light source, but an exposure apparatus equipped with a shorter wavelength ArF excimer laser (wavelength: 193 nm) is also being put into practical use.

 [0004] Further, when performing exposure, the depth of focus (DOF) is important as well as the resolution. The resolution R and the depth of focus δ are expressed by the following equations (1) and (2), respectively.

 R = k · λ / ΝΑ …… (1)

δ = ± k · λ ZNA ² · · · · (2) where λ is the wavelength of the exposure light and ΝΑ is the The numerical apertures k, k are process coefficients.

 1 2

 From the above equations (1) and (2), it can be seen that when the wavelength of the exposure light is shortened to increase the numerical aperture NA in order to increase the resolution R, the depth of focus δ becomes narrower. If the depth of focus δ is too narrow, it becomes difficult to match the substrate surface with the image plane of the projection optical system, and there is a possibility that the margin during the exposure operation becomes insufficient. Therefore, as a method of substantially shortening the exposure wavelength and increasing the depth of focus, for example, an immersion type exposure apparatus disclosed in Patent Document 1 below has been proposed.

 In this immersion type exposure apparatus, the space between the lower surface of the projection optical system and the substrate surface is filled with a liquid such as water or an organic solvent, and the wavelength power of the exposure light in the liquid lZn (n is The resolution is improved by utilizing the fact that the refractive index of the liquid is about 1.2-1.6), and the depth of focus is expanded by about η times.

 Patent Document 1: International Publication No. 99-49504 pamphlet

 Disclosure of the invention

 Problems to be solved by the invention

 [0007] The immersion exposure apparatus includes, for example, a liquid supply / recovery apparatus that supplies a liquid onto a substrate to be exposed and simultaneously recovers the supplied liquid. With this liquid supply / recovery device, at least a part of the substrate can be immersed in a predetermined amount of liquid whose temperature is controlled to be constant. The liquid collected by the liquid supply / recovery device is temporarily stored in a recovery section (recovery tank), and is further discharged by the recovery tank.

[0008] If the liquid is discharged from the collection tank while the liquid is being discharged, there is a possibility that vibration may be caused by the discharge of the liquid. If such vibrations occur during an operation that requires high-precision alignment, such as an exposure operation or substrate mark measurement, the final exposure accuracy (resolution, transfer fidelity, Accuracy, etc.). In addition, for example, the liquid supplied onto the substrate to be exposed is sucked and collected by a vacuum pump with a predetermined recovery force (negative pressure). May be disturbed. If the recovery power is disturbed, the amount of liquid recovered will fluctuate, causing a fluctuation in the amount of liquid supplied on the substrate to be exposed, which may also reduce the exposure accuracy. is there. [0009] Since the amount of liquid that can be calmed and can be temporarily stored in the recovery tank is limited, as the amount of liquid increases, the recovery tank power also overflows. Conversely, when the amount of liquid stored in the collection tank is less than the predetermined amount, both the liquid and air are discharged from the collection tank, or only air is discharged from the collection tank. Discharge systems (eg, pumps) are adversely affected and may be damaged in some cases.

 [0010] The present invention has been made in view of the above circumstances, and discloses an exposure apparatus, an exposure method liquid processing method, an exposure method using the liquid processing method, and an exposure apparatus capable of appropriately discharging the collected liquid. It is an object to provide a device manufacturing method using the exposure apparatus.

 Means for solving the problem

 [0011] In order to solve the above problems, an exposure apparatus according to a first aspect of the present invention includes an exposure apparatus (EX) that exposes a substrate (P) via a projection optical system (PL) and a liquid (w). At this time, the liquid supplied to the image plane side of the projection optical system is recovered to the recovery unit (41, 42, 61) via the recovery port (36, 36a, 36b, 36a ', 36b'). A liquid recovery device (CW), and a control device (CS) that controls a discharge operation of the liquid recovered by the recovery portion from the recovery portion in synchronization with an operation of the exposure device (EX). As a feature.

 According to the present invention, the liquid collected in the collection unit is discharged in synchronization with the operation of the exposure apparatus.

 An exposure apparatus according to a second aspect of the present invention is an exposure apparatus (EX) for exposing a substrate (P) via a projection optical system (PL) and a liquid (w), and an image plane of the projection optical system. Liquid recovery device (CW) for recovering the liquid supplied to the side through the recovery ports (36, 36a, 36b, 36a ', 36b') to the recovery section (41, 42, 61); A control device (CS) for controlling the operation of the liquid collection device, wherein the liquid recovery device has a plurality of recovery units, and the control device controls switching of a recovery unit connected to the recovery port. I have.

 According to the present invention, the plurality of collection units are switched by the control unit, and the liquid supplied to the image plane side of the projection optical system is collected by the control unit in the collection unit connected to the collection unit.

Further, the exposure apparatus according to the third aspect of the present invention uses a projection optical system (PL) and a liquid (w) In an exposure apparatus (EX) for exposing a substrate (P) by exposure to light, a liquid supply device (SW) for supplying a liquid to the image plane side of the projection optical system and a liquid supplied to the image plane side of the projection optical system A liquid recovery device (CW) for collecting the liquid in the collection section (41, 42, 61), a liquid level detection system (51, 52, 62) for detecting the surface position of the liquid collected in the collection section, A control device (CS) for controlling the liquid supply from the liquid supply device based on the detection result of the liquid level detection system.

 According to the present invention, the surface position of the liquid collected by the collection unit provided in the liquid collection device is detected by the liquid level detection system, and the liquid supply from the liquid supply device is controlled based on the detection result.

 A device manufacturing method according to the present invention is characterized by using any one of the exposure apparatuses described above. In order to solve the above problems, a liquid processing method according to a first aspect of the present invention is a liquid processing method in an exposure apparatus (EX) that exposes a substrate (P) via a liquid (w), A collecting step of collecting the collected liquid in a collecting section, and a discharging step of discharging the liquid collected in the collecting section to the collecting section in synchronization with the operation of the exposure apparatus. You.

 According to the present invention, the liquid collected in the collecting section is discharged from the collecting section in synchronization with the operation of the exposure apparatus.

 Further, a liquid processing method according to a second aspect of the present invention is a liquid processing method in an exposure apparatus (EX) that exposes a substrate (P) via a liquid (w), and collects a supplied liquid. (36, 36a, 36b, 36a ', 36b') and a first collecting unit (41) for connecting the collecting liquid to the first collecting unit to collect the supplied liquid; A second recovery step of connecting the recovery port to a second recovery section (42) different from the first recovery section, and recovering the supplied liquid to the second recovery section; and A discharging step of discharging the liquid collected in the first collecting section from the first collecting section.

According to the present invention, after the first recovery unit and the recovery port are connected to each other and the liquid supplied onto the substrate is recovered by the first recovery unit, the second recovery unit and the recovery port different from the first recovery unit are used. And the liquid supplied on the substrate is collected, and the first collection unit not connected to the collection port Force Liquid is discharged.

 Further, the liquid processing method of the present invention is a liquid processing method in an exposure apparatus (EX) for exposing a substrate (P) via a liquid (w), wherein a supply step supplied on the substrate includes: A collecting step for collecting the liquid supplied on the substrate to the collecting section (41, 42, 61); and, when the surface of the liquid collected in the collecting section reaches a predetermined position (WL1, WL11), And a stopping step of stopping the supply of the liquid. According to the present invention, when the surface of the liquid collected by the collection unit reaches a predetermined position, the supply of the liquid is stopped.

 An exposure method according to the present invention is characterized by using any one of the liquid processing methods described above.

 The invention's effect

 [0012] According to the present invention, an operation such as pattern transfer or the like that requires high accuracy is not adversely affected by vibration or the like. If it can be discharged!

 Further, according to the present invention, since the recovery section communicating with the recovery port is switched, even when an operation requiring high accuracy is performed, for example, the liquid is discharged from the recovery section not communicated with the recovery port. As a result, there is an effect that the collected liquid can be discharged without inducing the exposure accuracy.

 Further, according to the present invention, since the liquid supply with the power of the liquid supply device is controlled based on the detection result of the position of the surface of the liquid collected by the collection unit, for example, the overflow of the liquid with the collection unit power can be prevented. Can be.

 Further, according to the present invention, a reduction in the operation rate due to a defect in the exposure apparatus or the liquid discharging unit that can prevent exposure accuracy and the like caused by the discharging operation of the liquid collected in the collecting unit can be prevented. Since an exposure apparatus that can prevent such problems is used, there is an effect that a device having desired performance at a high yield can be manufactured at low cost.

 Brief Description of Drawings

FIG. 1 is a schematic configuration diagram of an exposure apparatus according to a first embodiment of the present invention.

[Figure 2] The relationship between the liquid supply mechanism SW and the liquid recovery mechanism CW and the projection area PR of the projection optical system PL It is a top view which shows an example of a positional relationship.

 FIG. 3 is a diagram for explaining an alarm threshold and a stop threshold set for a collection tank 41.

 FIG. 4 is a diagram showing a configuration near a liquid supply mechanism SW, a liquid recovery mechanism CW, and a projection optical system PL tip end according to a second embodiment of the present invention.

 FIG. 5 is a diagram for explaining a threshold value set for a collection tank provided in an exposure apparatus according to a second embodiment of the present invention.

 FIG. 6 is a flowchart showing an example of a micro device manufacturing process.

 FIG. 7 is a diagram showing an example of a detailed flow of step S13 in FIG. 6 in the case of a semiconductor device.

 Explanation of symbols

 [0014] 36 Recovery nozzle (recovery port) 41, 42, 61 Recovery tank (recovery section) 51, 52, 62 Water level sensor (water level detection means) CS main control system (control device) CW Liquid recovery mechanism (liquid recovery Device) SW liquid supply mechanism (liquid supply device) WL1 stop threshold (first water level) W L2 alarm threshold (second water level) WL11 water level (first water level) WL12 water level (second water level) W L13 water level (third water level) WL14 water level (4th water level)

 BEST MODE FOR CARRYING OUT THE INVENTION

 Hereinafter, an exposure apparatus, a liquid processing method, and a device manufacturing method according to an embodiment of the present invention will be described in detail with reference to the drawings.

 [First Embodiment]

 Hereinafter, embodiments according to the present invention will be described, but the present invention is not limited thereto. FIG. 1 is a schematic configuration diagram of an exposure apparatus according to a first embodiment of the present invention. As shown in FIG. 1, the exposure apparatus EX of the present embodiment includes a mask stage MST holding a mask M, a substrate stage PST holding a substrate P, and a mask M held by the mask stage MST. Illumination optical system IS illuminated by EL, exposure light Projection optical system PL that projects and exposes the pattern image of the mask M illuminated by EL onto the substrate P supported by the substrate stage PST, and the overall operation of the exposure equipment EX It is configured to include the main control system CS for overall control.

Further, the exposure apparatus EX of the present embodiment improves the resolution by substantially shortening the exposure wavelength. A liquid supply mechanism SW for supplying a liquid w onto a substrate P, a liquid supply mechanism SW for supplying a liquid w onto the substrate P, and a liquid w And a liquid recovery mechanism CW for recovering water. The exposure apparatus EX uses the liquid w supplied from the liquid supply mechanism SW on the substrate P including the projection area PR of the projection optical system PL during the exposure operation for transferring at least the pattern of the mask M onto the substrate P. Partially forms a liquid immersion area WR. Specifically, the exposure apparatus EX fills the space between the optical element 1 at the front end (end) of the projection optical system PL and the surface of the substrate P with the liquid w, and passes through the projection optical system PL and the liquid w. The pattern image of the mask M is projected onto the substrate P to expose the substrate P.

 The exposure apparatus EX shown in FIG. 1 is a scanning type that transfers a pattern formed on the mask M to the substrate P while synchronously moving the mask M and the substrate P in different directions (opposite directions) in the scanning direction. An exposure apparatus (a so-called scanning stepper). In the following description, an XYZ orthogonal coordinate system is set in the figure as necessary, and the positional relationship of each member will be described with reference to the XYZ orthogonal coordinate system. The direction that coincides with the optical axis AX of the projection optical system PL is the Z-axis direction, and the synchronous movement direction (scanning direction) between the mask M and the substrate P in a plane perpendicular to the Z-axis direction is the X-axis direction, the Z-axis direction, and The direction perpendicular to the X-axis direction (non-scanning direction) is set to the Y-axis direction. Also, the rotation (tilt) directions around the X, Y, and Z axes are set to the ΘX, ΘY, and θΖ directions, respectively. Here, the “substrate” includes a semiconductor wafer coated with a photoresist as a photosensitive material, and the “mask” includes a reticle on which a device pattern to be reduced and projected onto the substrate is formed.

Exposure apparatus て い る includes a main column 2 that supports mask stage MST and projection optical system PL. The main column 2 is set on a base plate 3 placed horizontally on the floor. The main column 2 is formed with an upper step 2a and a lower step 2b protruding inward. The illumination optical system IS is supported by a support column 4 fixed above the main column 2. The illumination optical system IS illuminates the mask M supported by the mask stage MST with the exposure light EL, and includes an exposure light source, an optical integrator for equalizing the illuminance of a light beam emitted from the exposure light source, It has a condenser lens that condenses the exposure light EL from the optical integrator, a relay lens system, and a variable field stop that sets the illumination area on the mask M by the exposure light EL in a slit shape. On the mask M The predetermined illumination area is illuminated by the illumination optical system IS with exposure light EL having a uniform illuminance distribution.

 In this embodiment, it is assumed that an ArF excimer laser (wavelength: 193 nm) is provided as a light source for exposure. Further, as the liquid w supplied between the projection optical system PL and the substrate P, pure water, which absorbs less Ar F excimer laser light, is used.

 The mask stage MST holds the mask M, and has an opening 5a at the center thereof, through which the pattern image of the mask M passes. A mask surface plate 7 is supported on the upper step 2 a of the main column 2 via a vibration isolation unit 6. An opening 5b through which the pattern image of the mask M passes is also formed in the center of the mask base 7. A plurality of gas bearings (air bearings) 8, which are non-contact bearings, are provided on the lower surface of the mask stage MST.

 The mask stage MST is supported in a non-contact manner on the upper surface (guide surface) 7a of the mask base 7 by an air bearing 8, and the light of the projection optical system PL is driven by a mask stage driving mechanism such as a linear motor. It is two-dimensionally movable in a plane perpendicular to the axis AX, that is, in the XY plane, and is micro-rotatable in the θZ direction. A movable mirror 9 is provided on the mask stage MST. Further, a laser interferometer 10 is provided at a position facing the movable mirror 9. The position of the mask M in the two-dimensional direction on the mask stage MST and the rotation angle in the θZ direction (including the rotation angles in the ΘX and ΘY directions in some cases) are measured in real time by the laser interferometer 10. The measurement result is output to the main control system CS. The main control system CS controls the position of the mask M supported by the mask stage MST by driving the mask stage driving mechanism based on the measurement result of the laser interferometer 10.

The projection optical system PL projects the pattern image of the mask M onto the substrate で at a predetermined projection magnification β, and includes an optical element (lens) 1 provided at the tip of the substrate Ρ. A plurality of optical elements are supported by the lens barrel 構成. In the present embodiment, the projection optical system PL is a reduction system whose projection magnification | 8 is, for example, 1Z4, 1Z5, or 1Z8. Note that the projection optical system PL may be either a unity magnification system or an enlargement system. Further, the projection optical system PL may be a displacement of a refractive system not including a reflective element, a reflective system not including a refractive element, or a catadioptric system including a refractive element and a reflective element. A flange portion FLG is provided on the outer peripheral portion of the lens barrel PK. The lens barrel base 12 is supported on the lower step 2 b of the main column 2 via a vibration isolation unit 11. The projection optical system PL is supported by the barrel base 12 by engaging the flange portion FLG of the projection optical system PL with the barrel base 12.

 The optical element 1 provided at the tip of the projection optical system PL is detachably (removably) attached to the lens barrel PK. The optical element 1 with which the liquid w of the immersion area WR comes into contact is formed of fluorite. Since fluorite has a high affinity for water, the liquid w can be brought into close contact with almost the entire liquid contact surface of the optical element 1. Accordingly, the optical path of the exposure light EL between the optical element 1 and the substrate P can be reliably filled with the liquid w. The optical element 1 may be made of quartz having high affinity with pure water. Also, the liquid contact surface of the optical element 1 may be subjected to a hydrophilic (lyophilic) treatment to further increase the affinity with the liquid w.

 [0025] A plate member 13 is provided around the optical element 1 so as to surround the optical element 1. The plate member 13 is provided for forming the liquid immersion region WR over a wide range and in a favorable manner. The surface facing the substrate P (ie, the lower surface) is a flat surface. The lower surface (liquid contact surface) of the optical element 1 provided at the tip of the projection optical system PL is also a flat surface, and the lower surface of the plate member 13 and the lower surface of the optical element 1 are arranged to be substantially flush. . Similarly to the optical element 1, the lower surface of the plate member 13 can be subjected to a surface treatment (lyophilic treatment).

 The substrate stage PST is configured to be able to move while sucking and holding the substrate P via the substrate holder 14, and has a plurality of gas bearings (air bearings) as non-contact bearings on its lower surface. Is provided. On the base plate 3, a substrate surface plate 17 is supported via a vibration isolation unit 16. The air bearing 15 sucks gas between the lower surface (bearing surface) of the substrate stage PST and the guide surface 17a, and an outlet for blowing gas (air) toward the upper surface (guide surface) 17a of the substrate surface plate 17. A constant gap is maintained between the lower surface of the substrate stage PST and the guide surface 17a by balancing the repulsion force of the gas blowing out of the outlet port with the suction force of the inlet port. .

[0027] That is, the substrate stage PST is mounted on the substrate surface plate (base member) 17 by the air bearing 15. The top surface (guide surface) is supported in a non-contact manner with respect to 17a, and can be moved two-dimensionally in a plane perpendicular to the optical axis AX of the projection optical system PL, that is, in the XY plane by a substrate stage drive mechanism such as a linear motor. And a small rotation in the θ Z direction. Further, the substrate holder 14 is provided so as to be movable in the Z-axis direction, the 0X direction, and the Y direction relative to the substrate stage PST. The substrate stage drive mechanism is controlled by the main control system CS. That is, the main control system CS controls the substrate holder 14 via the substrate stage drive mechanism, controls the focus position (Z position) and the tilt angle of the substrate P, and moves the surface of the substrate P to the image plane of the projection optical system PL. To fit.

 [0028] A movable mirror 18 is provided on the substrate stage PST (substrate holder 14), and a laser interferometer 19 is provided at a position facing the movable mirror 18. The two-dimensional position and rotation angle of the substrate P on the substrate stage PST are measured in real time by the laser interferometer 19, and the measurement results are output to the main control system CS. The main control system CS positions the substrate P supported by the substrate stage PST by driving the substrate stage drive mechanism including the linear motor based on the measurement result of the laser interferometer 19.

 Further, on the substrate stage PST (substrate holder 14), an auxiliary plate 20 is provided so as to surround the substrate P. The auxiliary plate 20 has a flat surface approximately the same height as the surface of the substrate P held by the substrate holder 14. By providing the auxiliary plate 20, the liquid w is held under the projection optical system PL by the auxiliary plate 20 and the substrate P even when exposing the edge region of the substrate P. A recovery port 21 connected to a recovery device (not shown) for recovering the liquid w flowing out of the substrate P is provided outside the auxiliary plate 20 on the upper surface of the substrate holder 14. The recovery port 21 is an annular groove formed so as to surround the auxiliary plate 20, in which a sponge-like member and a liquid absorbing member having a porous body and the like are arranged.

The substrate stage PST is movably supported by the X guide stage 22 in the X-axis direction. The substrate stage PST can be moved at a predetermined stroke in the X-axis direction by the X linear motor 23 while being guided by the X guide stage 22. At both ends in the longitudinal direction of the X guide stage 22, there are provided a pair of Y linear motors 24 capable of moving the X guide stage 22 together with the substrate stage PST in the Y axis direction. A non-contact gas bearing (air bearing) 28 is interposed between the stator of the Y linear motor 24 and the flat portion of the guide portion 25. The stator of the Y linear motor 24 is supported by the air bearing 28 in a non-contact manner with respect to the flat portion of the guide portion 25.

 [0031] Each of both sides of the substrate surface plate 17 in the X-axis direction is provided with a guide portion 25 formed in an L shape in a front view and guiding the movement of the guide stage 22 in the direction of the axis. I have. The guide part 25 is supported on the base plate 3. On the other hand, a concave guided member 26 is provided at each of both longitudinal ends of the lower surface of the X guide stage 22. The guide portion 25 is engaged with the guided member 26, and is provided such that the upper surface (guide surface) of the guide portion 25 and the inner surface of the guided member 26 face each other. A gas bearing (air bearing) 27 which is a non-contact bearing is provided on the guide surface of the guide portion 25, and the X guide stage 22 is supported in a non-contact manner with respect to the guide surface.

 Next, the liquid supply mechanism SW and the liquid recovery mechanism CW will be described. In the following description, the liquid w is mainly supplied onto the substrate 対 向 arranged facing the projection optical system PL, but another object (for example, the auxiliary plate 20 or the like) supplies the liquid w. The same applies to the case where it is arranged facing the system PL.

 The liquid supply mechanism SW supplies the liquid w between the projection optical system PL and the substrate P, and includes an ultrapure water production device 30, a temperature control device 31, and a supply nozzle 32. Ultrapure water production apparatus 30 is an apparatus for producing ultrapure water with high purity. The temperature control device 31 is a temperature control control unit that controls the temperature of the ultrapure water produced by the ultrapure water production device 30 at a constant level, a deaeration unit that deaerates the ultrapure water, a temperature control unit and a deaerated ultrapure water. And a pressurizing pump for sending ultrapure water. The supply nozzle 32 is disposed close to the surface of the substrate P and is connected to the temperature control device 31 via the supply pipe 33, and projects the ultrapure water sent from the temperature control device 31 as a liquid w. It is supplied between the optical system PL and the substrate P. The ultrapure water production equipment 30 and the temperature control equipment 31 do not necessarily need to be equipped with the liquid supply mechanism SW of the exposure equipment EX, but use equipment such as a factory where the exposure equipment EX is set instead of at least one of them. Good.

In the middle of the supply pipe 33, there is provided a flow meter 34 for measuring the amount of the liquid w supplied from the temperature control device 31 onto the substrate P (the liquid supply amount per unit time). The flow meter 34 monitors the amount of the liquid w supplied on the substrate P, and outputs the measurement result to the main control system CS. main The control system CS controls the liquid supply operation of the temperature control device 31 according to the monitoring result of the flow meter 34, and controls the supply amount of the liquid w supplied per unit time between the projection optical system PL and the substrate P. . A valve 35 for opening and closing the flow path of the supply pipe 33 is provided between the flow meter 34 and the supply nozzle 32 in the supply pipe 33. The opening and closing operation of the valve 35 is controlled by the main control system CS. The valve 35 in the present embodiment is of a so-called normally-off type that mechanically closes the flow path of the supply pipe 33 when the power of the exposure apparatus EX (main control system CS) is cut off due to, for example, a power failure. hand! / Puru.

 [0034] The liquid recovery mechanism CW recovers the liquid w on the substrate P supplied by the liquid supply mechanism SW, and includes a recovery nozzle 36, vacuum systems 38 and 39, a flow meter 40, and a recovery tank 41, 42 etc. The collection nozzle 36 is arranged close to the surface of the substrate P, and is connected to the collection tanks 41 and 42 via a collection pipe 43. The vacuum systems 38 and 39 include a vacuum pump, and the operation is controlled by the main control system CS. By driving the vacuum systems 38, 39, the liquid w on the substrate P is collected through the collection nozzle 36. In the present embodiment, the collecting nozzle 36 is configured to be able to collect only the liquid w, but the liquid w may be collected together with the surrounding gas (air). In that case, it is desirable to provide a separator for separating the recovered liquid w and gas into the liquid recovery mechanism CW so that only the gas is sucked into the vacuum systems 38 and 39. Further, as the vacuum systems 38 and 39, a vacuum system of a factory where the exposure apparatus EX is installed may be used without providing a vacuum pump in the exposure apparatus.

 The liquid w recovered by the recovery nozzle 36 is guided to the second recovery pipe 44 via the recovery pipe 43.

 The second recovery pipe 44 is branched into two recovery pipes 44a and 44b. One recovery pipe 44a is connected to the recovery tank 41, and the other recovery pipe 44b is connected to the recovery tank 42. Further, a flow meter 40 for measuring the amount of the recovered liquid w (the amount of recovered liquid per unit time) is provided in the middle of the second recovery pipe 44. The flow meter 40 monitors the amount of the liquid w recovered from the substrate P via the recovery nozzle 36 and outputs the measurement result to the main control system CS.

[0036] The main control system CS controls the operation of the vacuum system 38 or the vacuum system 39 according to the monitoring result of the flow meter 40, and is collected via the collection nozzle 36 from between the projection optical system PL and the substrate P. Liquid w Control the collection amount per unit time. In addition, valves 45 and 46 for opening and closing the flow paths of the recovery pipes 44a and 44b are provided in the recovery pipes 44a and 44b, respectively. The opening and closing operations of the valves 45 and 46 are controlled by the main control system CS. The recovery tanks 41 and 42 are for temporarily storing the liquid w recovered through the recovery nozzle 36, and are provided at their bottoms with discharge pipes 47 and 48 for discharging the stored liquid w. The discharge pipes 47, 48 are provided with valves 49, 50 for opening and closing the flow paths of the discharge pipes 47, 48, respectively. The discharge operation (discharge amount) of the valves 49 and 50 is controlled by the main control system CS so that the liquid volume (water level) in the recovery tanks 41 and 42 is kept below a certain level (for example, 30% of the total tank volume). It has become. The liquid w discharged from the discharge pipes 47 and 48 is, for example, discarded or cleaned, returned to the ultrapure water production apparatus 30 or the like, and reused.

Here, the configurations of the liquid supply mechanism SW and the liquid recovery mechanism CW will be described in detail. FIG. 2 is a plan view showing an example of the positional relationship between the liquid supply mechanism SW, the liquid recovery mechanism CW, and the projection area PR of the projection optical system PL. As shown in FIG. 2, the projection area PR of the projection optical system PL has a rectangular shape (slit shape) elongated in the Y-axis direction, and the projection area PR is located on the + X side so as to sandwich the projection area PR in the X-axis direction. One supply nozzle 32a-32c is arranged, and two collection nozzles 36a, 36b are arranged on the X side. The supply nozzles 32a-32c are connected to a temperature controller 31 via a supply pipe 33, and the recovery nozzles 36a, 36b are connected to a flow meter 40 via a recovery pipe 43.

 [0038] The supply nozzles 32a-32c 'are arranged at positions symmetrical to the supply nozzles 32a-32c with respect to the projection region PR, and the collection nozzles 36a', 36b are arranged at positions symmetrical to the collection nozzles 36a, 36b with respect to the projection region PR. 'Power is being placed. Supply nos and holes 32a- 32c and recovery nos and holes 36a 'and 36b' are arranged alternately in the Y-axis direction, and supply nozzles 32a'-32 and recovery nozzles 36a and 36b alternate in the Y-axis direction. Are arranged. The supply nozzles 32a 'to 32c' are connected to a temperature controller 31 via a supply pipe 33 ', and the recovery nozzles 36 and 36b' are connected to a flow meter 40 via a recovery pipe 43. A flowmeter 34 'and a valve 35' are provided in the middle of the supply pipe 33 ', similarly to the supply pipe 33.

The configuration and arrangement of the supply nozzle and the recovery nozzle are not limited to those described above, and may be any configuration that can fill the optical path space on the image plane side of the projection optical system PL with liquid. Ha !, good thing! The configuration in which the optical path space on the image plane side of the projection optical system PL is filled with a liquid is disclosed in, for example, a mechanism disclosed in WO2004Z053955 pamphlet or in European Patent Publication No.1420298. To the extent permitted by national laws of the designated country (or selected elected country) designated in the international application, the description in this specification is incorporated by reference to the disclosures in each of the above publications and their corresponding U.S. patents or U.S. patent application publications. Part of

Returning to FIG. 1, the recovery tanks 41 and 42 are provided with water level sensors 51 and 52 for detecting the water level of the liquid w stored inside (the surface position of the liquid w). The water level sensors 51 and 52 constantly monitor the water level of the liquid w stored in the recovery tanks 41 and 42, respectively, and output the detection results to the main control system CS. The main control system CS has an alarm threshold for issuing an alarm when the water level in the recovery tanks 41 and 42 is higher than a predetermined water level, and to prevent overflow of the liquid w from the recovery tanks 41 and 42. The stop threshold for stopping the supply of the liquid w is stored in advance in the table.

 FIG. 3 is a diagram for explaining an alarm threshold and a stop threshold set for the collection tank 41. Here, the alarm threshold value and the stop threshold value are similarly set for the force recovery tank 42 which will be described using the recovery tank 41 as an example. In FIG. 3, the imaginary line denoted by WL1 indicates the water level corresponding to the stop threshold, and the imaginary line denoted by WL2 indicates the water level corresponding to the warning threshold. As shown in FIG. 3, the water level WL1 corresponding to the stop threshold is set to be higher than the water level WL2 corresponding to the alarm threshold. That is, the stop threshold is set to a value larger than the warning threshold.

Further, the stop threshold value is set such that when the liquid supply operation of the temperature control device 31 is stopped and the supply of the liquid w is stopped by closing the valve 35 (35 ′), all the remaining liquid w is collected. Is set to That is, the stop threshold for the collection tank 41 is determined by the liquid w in the flow path from the valve 35 to the supply nozzle 32a-32c, the liquid w in the flow path from the valve 35 'to the supply nozzle 32a'-32c', The liquid w on P and the force of the recovery nozzles 36a, 36b, 36a ', 36b' are also set to values that allow the recovery tank 41 to recover the liquid w in the flow path to the recovery tank 41. The size of the collection tank should be determined so that the stop threshold can be set to about 80% of the recoverable amount of the collection tank 41. Returning to FIG. 1, the main control system CS always determines whether the detection results of the water level sensors 51 and 52 exceed the warning threshold or the stop threshold, and determines a temperature control device 31 in accordance with the determination. It controls the liquid supply operation, the opening and closing of valves 35 and 35 ', the operation of vacuum systems 38 and 39, the opening and closing of knobs 49 and 50, and the signal output to alarm device KD. Here, the alarm device KD is a device that issues an alarm in response to a signal output from the main control system CS, such as a warning light, an alarm sound, and a display. When an alarm is issued by the alarm device KD, for example, the operator can know that an abnormality has occurred in the collection tanks 41 and 42 before the liquid w overflows from the collection tanks 41 and 42.

 Further, the main control system CS performs control for switching the opening and closing of the valves 45 and 46 provided on the collection tubes 44a and 44b in synchronization with the operation of the exposure apparatus EX. In other words, when the liquid w is collected in the collection tank 41, the valve 45 is opened and the knob 46 is closed to connect the collection tank 41 to the collection nozzle 36, and the liquid w is collected in the collection tank 42. Performs control to open the knob 46 and close the valve 45.

 [0044] Two collection tanks 41 and 42 are provided, and the above switching control is performed based on the following reason. In other words, when the liquid w stored in the recovery tank that is connected in this manner is discharged, the vibration is caused by the discharge of the liquid w, and the collected nos and flaps 36 (36a, 36b, 36a,, 36b,) Or the recovery force (negative pressure) of the vacuum system 38 (or 39) is disturbed, and the amount of liquid on the image plane side of the projection optical system PL fluctuates. There are also forces that can be aroused. Transfer the pattern formed on the mask M onto the substrate P (exposure of the substrate P), or use a focus detection system to be described later to detect the position of the surface of the substrate P or to form an image on the substrate P using an alignment sensor. If vibration occurs or the amount of liquid w fluctuates during mark position measurement, the final exposure accuracy (resolution, transfer fidelity, overlay accuracy, etc.) will decrease. There is a risk of inviting. In the present embodiment, from the viewpoint of preventing this, a configuration is provided in which two recovery tanks are provided, and a recovery tank for recovering the liquid w without discharging the liquid stored therein is connected to the recovery nozzle 36, and is internally provided. The recovery tank for discharging the stored liquid is separated from the recovery nozzle 36, that is, the flow path to the recovery tank for discharging the liquid is closed.

Further, the exposure apparatus EX adjusts the position of the surface of the substrate P supported by the substrate stage PST. It has a focus detection system for detecting. The focus detection system includes a light projecting unit that projects a detection light beam from a diagonal direction onto the substrate P via the liquid w, and a light receiving unit that receives reflected light of the detection light beam reflected by the substrate P. . The light reception result of the focus detection system (light receiving unit) is output to the main control system CS. The main control system CS can detect the position information of the surface of the substrate P in the Z-axis direction and the tilt information of the substrate P in the ΘX and ΘY directions based on the detection result of the focus detection system.

 As the configuration of the focus detection system, for example, one disclosed in Japanese Patent Application Laid-Open No. 8-37147 can be applied. Further, the focus detection system may project the detection light beam onto the substrate P without passing through the liquid w.

 Further, the exposure apparatus EX includes an off-axis type alignment sensor on the side of the projection optical system PL. This alignment sensor is an FIA (Field Image Alignment) type alignment sensor, for example, irradiates a mark formed on the substrate P as a detection beam with a broadband wavelength light beam that also emits the power of a halogen lamp. The reflected light obtained from P is picked up by an image pickup device such as a CCD (Charge Coupled Device), and the picked-up image signal is supplied to the main control system CS. The main control system CS performs image processing on this image signal to calculate position information of the imaged mark. As the alignment sensor, for example, a sensor disclosed in Japanese Patent Application Laid-Open No. 465603/1994 can be applied.

 As shown in the partial cross-sectional view of FIG. 1, the liquid supply mechanism SW and the liquid recovery mechanism CW are separately supported by the lens barrel base 12. Thus, the vibration generated in the liquid supply mechanism SW and the liquid recovery mechanism CW is not transmitted to the projection optical system PL via the lens barrel base 12.

Next, a procedure for transferring the pattern of the mask M to the substrate P using the exposure apparatus EX having the above configuration will be described. When the exposure sequence is started, the mask M is loaded on the mask stage MST, and the substrate P is loaded on the substrate stage PST. Next, the position information of the mark formed on the substrate P loaded on the substrate stage PST is measured by using an alignment sensor, and based on the measurement result, the main control system CS sends an EGA (Even Noun 'Global'). (Alignment) calculation to determine the regularity of the array of all the shot areas set on the substrate P. Here, the EGA calculation is a typical preset on the substrate P All the shot areas set on the substrate P based on the position information of the marks (alignment marks) formed in association with each of the part (3-9) shot areas and their design information Is an arithmetic method for determining the regularity of the array in a statistical manner.

 [0049] Next, the main control system CS controls the opening and closing of the valves 45 and 46 provided in the recovery pipes 44a and 44b. Here, when the valve 45 is opened and the valve 46 is closed, only the recovery tank 41 communicates with the power recovery nozzles 36 and 36 (recovery nozzles 36a, 36b, 36a 'and 36b'). I do. After finishing the control of the valves 45 and 46, the main control system CS outputs a control signal to the temperature control device 31 provided in the liquid supply mechanism SW, and the ultrapure water produced by the ultrapure water production device 30 is produced. At a constant rate, and send out ultrapure water at a constant rate at a fixed rate per unit time. The ultrapure water sent from the temperature controller 31 is supplied to the optical element 1 at the distal end of the projection optical system PL via a supply pipe 33 (33 ') and a supply nozzle 32 (32a-32c, 32a'-32c'). It is supplied as a liquid w between the substrate P.

 [0050] Further, the main control system CS drives the vacuum system 38 of the liquid recovery mechanism CW with the supply of the liquid w by the liquid supply mechanism SW, and the recovery nozzle 36 (36a, 36b, 36a ', 36b'). Then, a predetermined amount of the liquid w is collected in the collection tank 41 per unit time via the collection pipe 43, the second collection pipe 44, and the collection pipe 44a. Thereby, an immersion area WR of the liquid w is formed between the optical element 1 at the tip of the projection optical system PL and the substrate P. Here, in order to form the liquid immersion area WR, the main control system CS sets the liquid supply mechanism SW so that, for example, the liquid supply amount on the substrate P and the liquid recovery amount on the substrate P become substantially the same. And the liquid recovery mechanism CW.

[0051] In a state where a fixed amount of liquid w is constantly supplied between the projection optical system PL and the substrate P (a state in which the optical path space on the image plane side of the projection optical system PL is filled with the liquid w). The main control system CS illuminates the mask M by emitting the illumination optical system IS force and the exposure light EL, and projects an image of the pattern of the mask M onto the substrate P via the projection optical system PL and the liquid w. During scanning exposure, a partial pattern image of the mask M is projected onto the projection area PR, and the mask M moves at a speed V in the −X direction (or + X direction) with respect to the projection optical system PL. Synchronously, the substrate P moves in the + X direction (or -X direction) at a speed ι8 · ν (| 8 is a projection magnification). When scanning exposure for one shot area is completed, the main control system CS moves the substrate stage PST stepping. Then, the next shot area is moved to the scanning start position, and thereafter, exposure processing for each shot area is sequentially performed in the same manner in a step-and-scan manner.

 In the present embodiment, the liquid w is set to flow in the same direction as the moving direction of the substrate P.

 That is, when scanning exposure is performed by moving the substrate P in the scanning direction SD1 (X direction) in FIG. 2, the supply pipe 33, the supply nozzles 32a to 32c, the recovery nozzles 36a and 36b, and the recovery pipe 43 are used. The liquid w is supplied and recovered by the liquid supply mechanism SW and the liquid recovery mechanism CW by using the. That is, when the substrate P moves in the −X direction, the liquid w is supplied between the projection optical system PL and the substrate P from the supply nozzle 32 (32a-32c), and the liquid w Is collected from the collection nozzle 36 together with the surrounding gas, whereby the liquid w flows in the −X direction so as to fill the space between the optical element 1 at the tip of the projection optical system PL and the substrate P.

On the other hand, when scanning exposure is performed by moving the substrate P in the scanning direction SD2 (+ X direction) in FIG. 2, the supply pipe 33 ′, the supply nozzle 32a′-32c ′, and the collection nozzle 36a ′ , 36b ', and the recovery pipe 43, the supply and recovery of the liquid w by the liquid supply mechanism SW and the liquid recovery mechanism CW are performed. That is, when the substrate P moves in the + X direction, the liquid w is supplied between the projection optical system PL and the substrate P from the supply nozzle 32 (32-32c '), and the substrate P The upper liquid w is recovered together with the surrounding gas from the recovery nozzle 36, whereby the liquid w flows in the + X direction so as to fill the space between the optical element 1 at the tip of the projection optical system PL and the substrate P. .

 By supplying the liquid w using the method described above, for example, the liquid w supplied through the supply nozzles 32a-32c is connected to the optical element 1 and the substrate P with the movement of the substrate P in the X direction. Therefore, the liquid w can be easily supplied between the optical element 1 and the substrate P even if the supply energy of the liquid supply mechanism SW (temperature control device 31) is small. By switching the direction in which the liquid w flows (supply nozzle) according to the scanning direction, the substrate P can be scanned in either the + X direction or the X direction between the optical element 1 and the substrate P. Can be filled with sufficient liquid w.

In addition, during the exposure processing or the like, the liquid w is supplied from the supply nozzle 32 of the liquid supply mechanism SW, and the flow meter 34 (34 ′) provided in the liquid supply mechanism SW for a while. Measurement result, The measurement result of the flow meter 40 provided in the liquid recovery mechanism CW is output to the main control system CS. The main control system CS obtains the measurement result of the flow meter 34 (34 '), that is, the amount of liquid supplied onto the substrate P via the supply nozzle 32 of the liquid supply mechanism SW, and the measurement result of the flow meter 40, The amount of liquid recovered from the substrate P via the recovery nozzle 36 of the liquid recovery mechanism CW is compared, and the knob 35 (35 ') of the liquid supply mechanism SW is controlled based on the comparison result.

 Specifically, the main control system CS calculates the liquid supply amount onto the substrate P (the measurement result of the flow meter 34 (34 ')) and the liquid recovery amount of the force on the substrate P (the measurement result of the flow meter 40). ) Is obtained, and the valve 35 (35 ') is controlled based on whether the obtained difference exceeds a preset allowable value (threshold). In the present embodiment, as described above, the main control system CS controls the liquid supply mechanism SW and the liquid recovery mechanism so that the amount of liquid supplied onto the substrate P and the amount of liquid recovered on the substrate P are substantially the same. Since each of the CWs is controlled, the liquid supply operation by the liquid supply mechanism SW and the liquid recovery operation by the liquid recovery mechanism CW are normally performed. It becomes.

 When the obtained difference is equal to or larger than the allowable value, that is, when the liquid recovery amount is extremely small compared to the liquid supply amount, the main control system CS may sufficiently generate an abnormality in the recovery operation of the liquid recovery mechanism CW. Judge that liquid w has not been collected. At this time, the main control system CS determines that an abnormality such as a failure has occurred in the vacuum system 38 (39) of the liquid recovery mechanism CW, for example, and the liquid recovery mechanism CW cannot recover the liquid w normally. In order to prevent the leakage of w, the valve 35 (3) of the liquid supply mechanism SW is operated to cut off the flow path of the supply pipe 33 (33 ^), and the liquid w is supplied to the substrate P by the liquid supply mechanism SW. Stop supply. As described above, the main control system CS compares the amount of the liquid w supplied onto the substrate P from the liquid supply mechanism SW with the amount of the liquid w recovered by the liquid recovery mechanism CW. Based on this, the liquid recovery mechanism CW detects an abnormality in the recovery operation of the CW, and the supply of the liquid w becomes excessive. When the abnormality is detected, the supply of the liquid w to the substrate P is stopped. Accordingly, it is possible to prevent the liquid w from leaking out of the substrate P and the substrate stage PST, or to penetrate the liquid w into an undesired portion, or to prevent the damage caused by such leakage or penetration.

When the liquid supply amount is extremely small compared to the liquid recovery amount, the liquid supply mechanism SW It may be determined that an abnormality has occurred in the supply operation of the liquid supply mechanism SW, and the valve 35 (35 ') of the liquid supply mechanism SW may be operated to shut off the flow path of the supply pipe 33 (33').

 [0058] The liquid w guided from the recovery pipe 43 to the second recovery pipe 44 is temporarily stored in the recovery tank 41 via the recovery pipe 44a. When the exposure processing for all shot areas set on the substrate P is completed, the main control system CS stops the liquid supply operation of the temperature control device 31 and performs only the operation of recovering the liquid w by the liquid recovery mechanism CW. Then, the liquid w on the substrate P and the liquid w between the collecting nozzle 36 and the collecting tank 41 are collected in the collecting tank 41.

 When the recovery operation is completed, the main control system CS stops the liquid recovery operation of the liquid recovery mechanism CW, and then performs control to switch the valves 45 and 46 between open and closed. That is, control is performed to close the valve 45 and open the valve 46. As a result, only the recovery tank 42 is in a state of being in communication with the recovery nozzle 36 (recovery nozzles 36a, 36b, 36a ', 36b'). During the switching between the knurls 45 and 46, the substrate P on the substrate stage PST is unloaded and a new substrate P is loaded on the substrate stage PST. When a new substrate P is loaded, the main control system CS restarts the liquid supply operation by the liquid supply mechanism SW and the liquid recovery operation by the liquid recovery mechanism CW, and performs the exposure processing in the same procedure as described above. Start.

 When the switching control of the valves 45 and 46 is completed, the main control system CS opens the no-reb 49 in parallel with the exposure processing, and collects the nos and the nos 36 (the nos and the nos 36a and 36a, The liquid w stored in the recovery tank 41 not communicating with 36b, 36a ', 36b') is discharged. In this case, since the valve 45 provided in the recovery pipe 44a connected to the recovery tank 41 is closed, the vibration caused by the discharge of the liquid w and the recovery power (negative pressure) of the vacuum system 39 are not disturbed. Thereby, it is possible to suppress the exposure accuracy from being deteriorated due to the vibration and the change in the amount of the liquid w.

When the operation of discharging the liquid w from the collection tank 41 is completed and the exposure processing for all the shot areas set on the substrate P on the substrate stage PST is completed, the main control system CS restarts the temperature control device 31 The liquid supply operation is stopped, and the liquid w remaining on the substrate P or the like is recovered, and the liquid recovery operation of the liquid recovery mechanism CW is stopped. Then, the valves 45 and 46 are switched between open and closed to control the valve 45 to be opened and the valve 46 to be closed, so that only the recovery tank 41 has the power recovery nos and nos 36 (recovery nos and nos 36a, 36b, 36a ', 36b ') State. In addition, during switching between knurls 45 and 46, unloading of substrate P and loading of new substrate P are performed. Further, in parallel with the exposure operation of the exposure apparatus EX, the valve 50 is opened, and the collecting nozzle 36 (collecting nozzle, 36a, 36b, 36a ', 36b') is collected. The liquid w stored in the tank 42 is discharged. When the above operation is completed, the exposure process for the substrate P on the substrate stage PST is performed again, and the above operation is repeated for the exposure process for the plurality of substrates P.

 [0062] The detection results of the water level sensors 51, 52 provided in the recovery tanks 41, 42 are always output to the main control system CS. The main control system CS compares the detection results of the water level sensors 51 and 52 with the preset alarm threshold and stop threshold, and determines whether each detection result exceeds the alarm threshold or stop threshold. to decide. For example, if it is determined during the exposure of the substrate P that the water level in the collection tank 42 communicating with the collection nozzle 36 has exceeded the alarm threshold, the main control system CS outputs a signal to output the alarm device KD Drive. When a signal is output from the main control system CS, an alarm is issued from the alarm device KD by a warning light, alarm sound, display, or the like. Thus, it is possible to notify an operator or the like that the liquid w may overflow from the recovery tanks 41 and 42, or that an abnormality has occurred in the liquid supply mechanism SW or the liquid recovery mechanism CW of the exposure apparatus EX.

 [0063] For example, when the water level in the collection tank 42 reaches the alarm threshold, the main control system CS performs exposure until the exposure processing is completed for the shot area being exposed, the wafer being exposed, or the lot being exposed. The processing is continued, and then the knob 50 is opened to stop the exposure processing, and the stored liquid w is discharged from the recovery tank 42. The point at which the exposure process is continued and interrupted depends on the size of the recovery tanks 41 and 42 (recovery capacity), the set value of the alarm threshold, and the amount of liquid w recovered per unit time. Should be set.

Further, during the exposure of the substrate P, for example, if the water level of the collection tank 42 communicating with the collection nozzle 36 reaches the stop threshold, the main control system CS immediately stops the exposure operation, The liquid supply operation of the temperature controller 31 is stopped, and the supply of the liquid w is stopped by closing the valve 35 (35 '), and the substrate stage PST is stopped under the projection optical system PL. Then, the liquid w on the substrate P and the liquid w between the collecting nozzle 36 and the collecting tank 42 are collected, and the valve 50 is opened to discharge the liquid w from the collecting tank 42. In this case, from the collection tank 41 Needless to say, the discharge of the liquid w may be performed in parallel. As described above, the stop threshold is set to a value that allows recovery of the remaining liquid W or more.

The liquid w does not overflow from the recovery tanks 41 and 42 even if the liquid w is recovered more than the time when it is determined that any one of the water levels 41 and 42 exceeds the stop threshold.

As described above, in the present embodiment, the valves 45 and 46 are switched to switch the collection tanks 41 and 42 communicating with the collection nozzle 36 (collection nozzles 36a, 36b, 36a 'and 36b'). , Recovery Nos, No 36 (Recover Nos, No 36a, 36b, 36a ', 36b'; Because of the discharge, fluctuations in the vibration and the recovery force (negative pressure) of the vacuum system 38 or 39 due to the discharge of the liquid w can be suppressed, so that, for example, measurement of mark position information by an alignment sensor or mask Μ Fluctuations of the liquid w supplied on the substrate ぐ do not affect the operation that requires high precision alignment such as pattern transfer (A change in refractive index and a change in liquid volume due to vibration). It does not make it worse.

 Further, the liquid level of the liquid stored in the collection tank (41 or 42) communicating with the collection nozzle 36 is monitored, and when the liquid level reaches a predetermined threshold, the liquid supply from the liquid supply mechanism SW is stopped. At the same time, since the liquid discharging operation of the recovery tank communicating with the recovery nozzle 36 is performed, the liquid in the recovery tank (41 or 42) can be prevented from overflowing. When the water level in the recovery tank (41 or 42) communicating with the recovery nozzle 36 reaches the stop threshold, the valve (45 or 46) is immediately closed to stop the recovery of the liquid w on the substrate と と も に. The collection nozzle 36 can be communicated with the collection tank 36! ,.

In the above embodiment, the switching control of the valves 45 and 46 is performed every time the exposure process on the substrate Ρ is completed in synchronization with the operation of the exposure device が. However, the sequence of the exposure process and the capacity of the collection tank are performed. It is desirable to change the switching control to the valves 45 and 46 according to the conditions. For example, when the number of shots set on the substrate 多 い is large, the switching control of the valves 45 and 46 is performed each time the exposure processing for a predetermined number of shots is completed, and the number of shots set on one substrate Ρ is increased. If the number is small, the switching control of the valves 45 and 46 may be performed each time the exposure processing for a plurality of sheets or lots is completed. Further, in the above-described embodiment, the second recovery pipe 44 is branched into the recovery pipe 44a and the recovery pipe 44b, and each is connected to the recovery tank 41, 42 via the valve 45, 46. However, the collection pipe forming the flow path from the collection nozzles 36a, 36b to the collection tank 41 and the collection pipe forming the flow path to the collection tank 42 with the force of the collection nozzles 36a ', 36b' are separately arranged, For example, when the substrate P moves in the −X direction, the liquid w collected from the collection nozzles 36a and 36b flows into the collection tank 41, and when the substrate P moves in the + X direction, the force of the collection nozzles 36a ′ and 36b ′ also increases. The collected liquid w may be allowed to flow to the collection tank 42. In this case, the liquid w can be discharged from the collection tank 41 when the substrate P moves in the + X direction, and the liquid w can be discharged from the collection tank 42 when the substrate P moves in the −X direction. .

 [0068] In addition, the draining operation of the recovery tank (41 or 42) is performed as follows: recovery nos, no. 36 (recovery nos, no. 36a, 36b, 36a,, 36b '; It is needless to say that it is preferable to avoid as much as possible during operations that require high precision, such as when measuring the mark on the substrate 及 び using the alignment sensor and transferring the pattern on the mask 等. The discharging operation of the liquid w with the force of the collection tank (41 or 42) not connected to the nozzle 36 is performed, for example, by performing mark measurement on the substrate Ρ using an alignment sensor, when transferring the pattern of the mask Μ. When not performed, more specifically, when loading and unloading substrate ((during replacement of substrate）), after detecting the above alignment mark, start EGA calculation and start pattern transfer of mask Μ. Or until multiple substrates P It is desirable to perform the operation in synchronization with the operation of the exposure apparatus at the timing such as the preparation period of a lot, etc. By discharging the liquid w from the collection tank at such timing, high accuracy such as pattern transfer is required. In addition, in the above-described embodiment, the apparatus is provided with three or more recovery tanks that switch between the two recovery tanks. It may be used by switching as appropriate.

 [Second Embodiment]

Next, an exposure apparatus according to a second embodiment of the present invention will be described with reference to FIG. FIG. 4 shows an essential part extracted from the exposure apparatus EX shown in FIG. The exposure apparatus of the present embodiment has the same overall configuration as the above-described exposure apparatus according to the first embodiment of the present invention. The force recovery tank is one, and the water level threshold set for the recovery tank is set. Are different. That is, in the second embodiment, the vacuum system 39, the recovery tank 42, the recovery pipe 44b, the discharge pipe 48, the valve 50, the water level sensor 52, and the connection between these and the main control system CS are omitted. Further, in the present embodiment, one collection tank 61 is provided instead of the collection tank 41 shown in FIG. Other configurations are the same as those in FIG.

FIG. 5 is a diagram for explaining a threshold value set for the collection tank 61 provided in the exposure apparatus according to the second embodiment of the present invention. The configuration of the recovery tank 61 shown in FIG. 5 is almost the same as that of the recovery tank 41 shown in FIG. That is, the water level sensor 62 is provided inside the recovery tank 61, and the detection result of the water level sensor 62 is output to the main control system CS. At the bottom, a discharge pipe 63 for discharging the liquid w stored in the recovery tank 61 is provided, and the discharge pipe 63 is provided with a valve 64 for opening and closing the flow path of the discharge pipe 63. . The opening and closing operation of the valve 64 is controlled by the main control system CS. The liquid w discharged from the discharge pipe 63 is, for example, discarded or cleaned, returned to the ultrapure water production device 30 or the like, and reused.

 In the present embodiment, four thresholds of the first to fourth thresholds are set for the water level detected by the water level sensor 62 in the main control system CS. In FIG. 5, the imaginary line denoted by WL11 corresponds to the water level corresponding to the first threshold, the imaginary line denoted by WL12 corresponds to the water level corresponding to the second threshold, and the imaginary line denoted by WL13 corresponds to the third threshold. The imaginary line with the water level and the symbol WL14 is the water level corresponding to the fourth threshold. The water level WL11 is the same as the water level set for the stop threshold shown in FIG. 3, and the water level WL12 is the same as the water level set for the warning threshold shown in FIG. That is, when the water level in the recovery tank 61 becomes higher than WL12, a signal is output from the main control system CS to the alarm device KD, and an alarm is issued from the alarm device KD. When the water level becomes higher than WL11, the liquid w from the liquid supply mechanism SW Supply of liquid is stopped, and liquid w is collected. Note that, similarly to WL1 set in the first embodiment, after stopping the supply of the liquid w, the water level WL11 can collect all of the liquid w remaining on the substrate P into the collection tank 61. The water level is set. Preferably, the water level WL11 is set to about 80% of the recovery capacity of the recovery tank 61.

[0072] The water level WL13 is set to a lower water level than the water level WL12, and the water level WL14 is set to a lower water level than the water level WL13. Third set against water level WL 13 The threshold value is a threshold value used for performing control so that a certain amount or more of the liquid w is stored in the collection tank 61. That is, the main control system CS controls the valve 64 such that the water level of the liquid w stored in the recovery tank 61 is maintained between the water levels WL12 and WL13 as much as possible. The fourth threshold value set for the water level WL14 is a threshold value that determines the minimum amount of the liquid w stored in the recovery tank 61. If the liquid w in the recovery tank 61 falls below a predetermined amount, gas may be discharged together with the liquid w from the recovery tank 61, or only the gas may be discharged, which may adversely affect the discharge system. Even if the water level of the liquid w in the recovery tank 61 falls below the water level WL13, which corresponds to the third threshold, due to the cause, set the fourth threshold to secure the minimum water volume!

 In the above configuration, the transfer of the pattern of the mask M onto the substrate P is performed in the same procedure as in the first embodiment described above. In other words, the mask M is loaded on the mask stage MST and the substrate P is loaded on the substrate stage PST, and the positional information of the mark formed on the substrate P is measured using the alignment sensor V. An operation is performed to determine the regularity of the arrangement of the shot areas on the substrate P. Next, the recovery tank 61 is opened by the force of the vanoleb 45 provided in the recovery pipe 44a, and the recovery tank 61 is communicated with the recovery nos and the recovery 36 (the recovery nos, the recovery 36a, 36b, 36a ', and 36b'). In the present embodiment, the valve 45 may be kept open, that is, the collection nozzle 36 and the collection tank 61 may be kept in communication.

 Next, by driving the liquid supply mechanism SW, the optical element 1 provided at the distal end of the projection optical system PL via the supply pipes 33 and 3 and the supply nozzle 32 (32a-32c, 32a'-32c '). The liquid w is supplied between the substrate P and the liquid supply mechanism SW is driven to collect the liquid w supplied onto the substrate し て through the collection nozzle 36 (36a, 36b, 36a ', 36b'). Collected in tank 61. In a state in which a constant amount of liquid w is constantly supplied between the projection optical system PL and the substrate P, the mask stage MST and the substrate stage PST are scanned while the mask M is illuminated by the exposure light EL. An image of the pattern of the mask M is projected onto the substrate P via the projection optical system PL and the liquid w. Hereinafter, similarly, the exposure processing for each shot area is sequentially performed by the step-and-scan method.

When the exposure of all the shot areas on the substrate P is completed, the liquid w supplied onto the substrate P is discharged to the collection nozzle 36 (collection nozzles 36a, 36b, 36a ′, 36b ′) as in the first embodiment. ) Via Then, the collected nos, No. 36 (recovery Nos, No. 36a, 36b, 36a ', 36b'; collected in a collecting tank 61 which communicates with the Η.

 When the collection of the liquid w on the substrate 終了 is completed, the exchange of the substrate 、, that is, the unloading of the exposed substrate and the loading of the substrate to be exposed next are performed. The liquid w is discharged from the collection tank 61 during the replacement of the substrate in synchronization with the operation of the exposure apparatus 基板. That is, the main control system CS opens the valve 64 and discharges the liquid w until the detection result of the water level sensor 62 indicates the water level WL13. When the detection result of the water level sensor 62 becomes the water level WL13, the main control system CS closes the valve 64 and ends the operation of discharging the liquid w from the recovery tank 61. When the substrate exchange operation and the liquid discharge operation of the recovery tank 61 are completed, the main control system CS starts supplying the liquid w onto the substrate Ρ, and in the same manner as described above, the plurality of shot areas on the substrate Ρ Exposure processing is sequentially performed. Similarly, liquid immersion exposure processing is performed on a plurality of substrates, and during the substrate replacement operation, the liquid discharging operation of the collection tank 61 is performed in parallel with the operation.

 [0077] The detection result of the water level sensor 62 provided in the recovery tank 61 is constantly output to the main control system CS, and the main control system CS compares the detection result of the water level sensor 62 with the first to eleventh set in advance. It is compared with the fourth threshold value to determine whether or not the detection result exceeds the first-first to fourth threshold values. If it is determined that the water level in the recovery tank 61 exceeds the second threshold, the main control system CS outputs a signal to drive the alarm device KD, as in the first embodiment. As a result, an alarm is issued from the alarm device KD by a warning light, an alarm sound, a display, or the like.

 When an alarm is issued, the exposure processing is continued until the exposure processing for the shot area being exposed, the wafer being exposed, or the lot being exposed is completed, and thereafter, the exposure processing is interrupted. The liquid w stored in the recovery tank 61 is discharged. The discharge of the liquid w is controlled so that the water level of the liquid w in the recovery tank 61 does not fall below the water level WL13 corresponding to the third threshold. In this way, the water level of the liquid w in the recovery tank 61 is maintained between the water levels WL12 and WL13. The point at which the exposure processing is continued and interrupted depends on the size of the recovery tank 61 (recovery capacity), the set value of the second threshold value, the amount of liquid w recovered per unit time, and the like. Should be set.

Further, the water level of the recovery tank 61 exceeds the water level WL12 and corresponds to the first threshold value WL11 When it is determined that the temperature has reached the maximum, the main control system CS immediately stops the liquid supply operation of the temperature control device 31 and closes the valves 35 and 35 'to stop the supply of the liquid w, and the substrate stage PST Is stopped under the projection optical system PL. Then, the liquid _w or the like remaining on the substrate P is collected through the collection nozzle 36 (collection nozzles 36a, 36b, 36, 36b '), and the collected nozzle 36 (collection nozzle, 36a, 36b, 36a', 36b '). H Recover tank 61 that communicates with the tank [Recover and open valve 64 to discharge liquid from recovery tank 61 until the water level sensor detects a water level of WL13. Since the liquid w is set to a value that can recover more than the liquid w, even if all the liquid w remaining on the substrate P is recovered from the time when the supply of the liquid w is stopped, the recovery tank 61 The liquid w does not overflow When the water level in the recovery tank 61 reaches the stop threshold, the valve 45 may be closed immediately and the valve 64 may be opened to start discharging the liquid from the recovery tank 61. If the water level in recovery tank 61 reaches the stop threshold, It is possible that the alarm device KD, which should be triggered when the 61 water level reaches the alarm threshold, has failed.Therefore, another alarm device (warning light, alarm sound, display, etc.) was installed. Thus, an alarm may be issued when the stop level of the water level in the recovery tank 61 is reached.

 Further, when the water level of the liquid w stored in the recovery tank 61 during the discharging operation of the recovery tank 61 exceeds the water level WL 13 corresponding to the third threshold value and reaches the water level WL 14 corresponding to the fourth threshold value First, the main control system CS closes the knob 64 provided in the discharge pipe 63 to stop the discharge of the liquid w. As described above, even if the water level of the liquid w exceeds the water level WL13 corresponding to the third threshold value due to the failure of the water level sensor 62, malfunction due to external noise, or other causes while the liquid w is being discharged. When the level of the liquid w stored in the recovery tank 61 reaches the water level WL14 corresponding to the fourth threshold value, the valve 64 is immediately closed and a certain amount of the liquid w is stored in the recovery tank 61. State is secured. By vigorous control, it is possible to prevent the gas from being discharged together with the liquid w from the recovery tank 61, or to prevent only the gas from being discharged, without affecting the discharge system! / ,.

As described above, in the present embodiment, the liquid discharging operation of the collection tank 61 is performed during the substrate exchange operation in synchronization with the operation of the exposure apparatus EX. It is possible to prevent a decrease in exposure accuracy due to fluctuations in the liquid recovery power (negative pressure) due to vibrations caused by vibration. Also However, in the present embodiment, problems such as the liquid w overflowing from the collection tank 61 and the discharge system of the collection tank 61 being damaged due to the liquid w in the collection tank 61 being less than a predetermined amount are caused. As a result, the operation rate of the exposure apparatus EX does not decrease. In the above-described second embodiment, four thresholds are set for the water level of the recovery tank 61. However, the recovery tanks 41 and 42 of the first embodiment also have four thresholds as in the second embodiment. A threshold may be set.

 In the above-described second embodiment, the discharge operation of the recovery tank 61 is performed in synchronization with the operation of the exposure apparatus EX. The operation is not limited to the substrate exchange operation.During the exposure of the shot area on the substrate P, the mark measurement is performed using the alignment sensor. For example, between the start of EGA calculation and the start of exposure of the substrate P, during the preparation of a lot, or after the completion of exposure of a certain shot area on the substrate P The liquid discharging operation may be performed before the exposure of the area is started.

In the first and second embodiments described above, the discharge from the recovery tanks 41, 42, and 61 controls the knobs 49, 50, and 64 provided in the outlet pipes 47, 48, and 63. However, a gear pump or the like may be used instead of a valve. Further, a check valve may be arranged between the valve (gear pump) and the recovery tank to prevent backflow. In the above-described embodiment, a drain pan (liquid receiving member) for preventing diffusion of the liquid w overflowing from the collection tanks 41, 42, 61 is disposed below the collection tanks 41, 42, 61. You may do it. The size of the drain pan (liquid holding capacity) may be determined according to the size of each recovery tank. Preferably, a drain pan having a recovery capacity of about 110 to 120% of the maximum liquid recovery amount of each recovery tank is arranged. Further, a liquid (water) detection sensor may be disposed inside the drain pan to detect that the liquid overflows from the recovery tanks 41, 42, 61. In this case, it is desirable that the output of the liquid detection sensor disposed inside the drain pan is also supplied to the main control system CS. When the liquid detection sensor disposed inside the drain pan detects overflow of the liquid, the main control system CS immediately stops the liquid supply operation of the temperature control device 31 and closes the valve 35. It is desirable to stop the supply of the liquid w and stop the substrate stage PST below the projection optical system PL. Thereby, it is possible to prevent the liquid w from overflowing from the drain pan.

 In the first and second embodiments described above, a configuration in which one ultrapure water production apparatus 30 and one temperature control apparatus 31 are provided for one exposure apparatus EX has been described. When a plurality of exposure devices EX are provided, a temperature control device 31 is provided for each exposure device, and these temperature control devices 31 are connected to, for example, one ultrapure water production device 30 provided in a factory. It is desirable to have a connection configuration.

 Since the exposure apparatuses EX of the first and second embodiments use pure water, it is desirable to use a water level sensor such as an optical fiber system that can use pure water as the water level sensor. However, when the purity of the water recovered in the recovery tanks 41, 42, 61 is low, a water level sensor such as a capacitance type or an electric resistance type can be applied. Further, the water level sensor may be capable of continuously monitoring the water level in the recovery tank, or may be provided with a water level sensor for detecting the water level corresponding to the first to fourth threshold values as described above.

 [0086] In the first and second embodiments described above, the water level sensor is applied to the collection tanks 41, 42, and 61 that store the liquid w collected by the collection nozzle 36 on the image plane side of the projection optical system PL. However, the present invention is not limited to this, and the present invention can be applied to other collection tanks such as a liquid trap (liquid collection tank) provided in the middle of a vacuum system for adsorbing the substrate P to the substrate stage PST. Further, the above-described first and second embodiments will be described in the case where the exposure apparatus EX performs an operation requiring high accuracy, and uses a recovery tank that discharges a liquid at a certain time. However, the configuration of the water level sensor and the setting of the threshold value in the above-described first and second embodiments, or the operation of the exposure apparatus EX according to the detection result of the water level sensor (for example, the liquid The stop of the supply, the stop of the exposure operation, etc.) can also be applied to an exposure apparatus having a collection tank capable of discharging the liquid regardless of the operation of the exposure apparatus EX.

In the above embodiment, since the illumination optical system IS includes the ArF excimer laser light source, pure water is used as the liquid w. Pure water can be easily obtained in large quantities at semiconductor manufacturing plants, etc., and can also be used for photoresist and optical elements (lenses) on the wafer W. There is an advantage that there is no adverse effect. In addition, since pure water has no adverse effect on the environment and has a very low impurity content, it can be expected to clean the W surface and the surface of the optical element provided on the tip end surface of the projection optical system PL. . In addition, since pure water in the factory may have a low level (purity of water), in such a case, the exposure apparatus itself may have an ultrapure water purification mechanism.

 [0088] The refractive index n of pure water (water) with respect to exposure light having a wavelength of about 193 nm is said to be approximately 1.44. When an ArF excimer laser light (wavelength 193 nm) is used as the light source of the exposure light, the refractive index n On the wafer W, the wavelength is shortened to lZn, that is, about 134 nm, and a high resolution is obtained. Furthermore, since the depth of focus is expanded to about n times, that is, about 1.44 times as compared with that in the air, if it is sufficient to secure the same depth of focus as that used in the air, the projection optical system PL The numerical aperture can be increased, and the resolution can be improved in this respect as well.

 Note that a KrF excimer laser light source or an F laser light source was used as the light source 1 for immersion exposure.

 2

 You can also be. When using an F laser light source, the liquid for immersion exposure is F laser

 It is sufficient to use a fluorine-based liquid such as a fluorine-based oil or perfluoropolyether (PFPE) that can transmit 22 light. In addition, use a projection optical system that is transparent to the exposure light and has the highest possible refractive index, and is stable against the photoresist applied to the PL, Ueno, and W surfaces (for example, cedar oil). It is also possible. In that case, a sensor that can detect the amount of liquid in the recovery tank may be used.

 As described above, when the liquid immersion method is used, the numerical aperture NA of the projection optical system may be 0.9-1.3. When the numerical aperture NA of the projection optical system is increased as described above, since the imaging characteristic may be deteriorated due to the polarization effect in the case of random polarized light, which has been conventionally used as the exposure light, polarized light may be used. It is desirable to use In that case, linearly polarized illumination is performed in accordance with the longitudinal direction of the line pattern of the mask's line 'and' space pattern, and the S-polarized component (polarization direction component along the longitudinal direction of the line pattern) is extracted from the mask pattern. It is preferable that a large amount of diffracted light is emitted.

[0091] If the space between the projection optical system and the resist applied to the substrate surface is filled with liquid! /, The space between the projection optical system and the resist applied to the substrate surface is filled with air (gas). //, which contributes to the improvement of contrast on the resist surface of the diffracted light of the S-polarized light component. Since the light transmittance of the projection optical system is increased, high imaging performance can be obtained even when the numerical aperture NA of the projection optical system exceeds 1.0. Further, it is more effective to appropriately combine a phase shift mask, such as an oblique incidence illumination method (particularly, a dipole illumination method) adapted to the longitudinal direction of a line pattern as disclosed in JP-A-6-188169.

[0092] Not only linearly polarized light (S-polarized light) aligned with the longitudinal direction of the mask line pattern but also a circle centered on the optical axis as disclosed in JP-A-6-53120. It is also effective to use a combination of a polarized illumination method and a grazing incidence illumination method that linearly polarizes in the tangential (circumferential) direction.

 In particular, in the case where a plurality of line patterns extending in different directions are mixed together with a line pattern extending only in a predetermined direction in the mask pattern, as disclosed in JP-A-6-53120, the optical axis By using both the polarized illumination method and the annular illumination method, which linearly polarizes the light in the tangential direction of a circle centered on, high imaging performance can be obtained even when the numerical aperture NA of the projection optical system is large.

In the above-described embodiment, an immersion exposure apparatus that locally fills the space between the projection optical system PL and the wafer W with a liquid is employed, which is disclosed in JP-A-6-124873. An immersion exposure apparatus for moving a stage holding a substrate to be exposed as described above in a liquid tank, and a liquid having a predetermined depth on a stage as disclosed in JP-A-10-303114. The present invention is also applicable to an immersion exposure apparatus in which a tank is formed and a substrate is held therein.

 [0094] Further, as disclosed in JP-A-10-163099, JP-A-10-214783, JP-T-2000-505958, and the like, separate substrates to be processed such as wafers are disclosed. It can also be applied to a twin-stage type exposure apparatus equipped with two stages that can be moved independently in the X and Y directions.

The present invention can be applied to an exposure apparatus provided with a measurement stage, which is mounted on the image plane side of the projection optical system by mounting a member for measurement and a sensor separately from the stage for holding the substrate P. An exposure apparatus provided with a measurement stage is disclosed in, for example, Japanese Patent Application Laid-Open No. 2000-164504 (corresponding to U.S. Application No. 09Z593,800), and is designed for use in designated countries (or selected selected countries) specified in this international application. To the extent permitted by national law, the above publication and this The disclosure in the US application corresponding to US Pat.

 [0095] Further, in the above embodiment, the case where the ArF excimer laser light source is used as the light source has been described as an example. However, other light sources such as a g-line (wavelength 436nm) and an i-line (wavelength 365nm) Ultra-high pressure mercury lamp or KrF excimer laser (wavelength 248 nm)

 2 High frequency generator for laser (wavelength 157nm), Kr laser (wavelength 146nm), YAG laser

 2

 Alternatively, a high frequency generator of a semiconductor laser can be used.

 [0096] In addition, a single-wavelength laser beam in the infrared or visible region where a DFB semiconductor laser or fiber laser power is also oscillated as a light source is amplified by, for example, a fiber amplifier doped with erbium (or both erbium and yttria). Alternatively, a harmonic converted to ultraviolet light using a nonlinear optical crystal may be used. For example, assuming that the oscillation wavelength of a single-wavelength laser is in the range of 1.51 to 1.59 m, the generation wavelength is in the range of 189 to 199 nm, the eighth harmonic, or the generation wavelength is in the range of 151 to 159 nm. The 10th harmonic is output.

 [0097] If the oscillation wavelength is in the range of 1.03-1.12 m, a seventh harmonic whose output wavelength is in the range of 147-160 nm is output. Assuming that it is within the range of 106 / zm, the generated harmonic is the 7th harmonic within the range of 157-158 m, that is, F laser light.

 Ultraviolet light having almost the same wavelength as 2 is obtained. In this case, as a single-wavelength oscillation laser, for example, an itbidium 'doped' fiber laser can be used.

[0098] Further, the glass material of the optical element provided in the illumination optical system IS and the glass material of the refraction member constituting the projection optical system PL may be fluorite (calcium fluoride: CaF 2) depending on the wavelength of the exposure light.

 2 or a fluoride crystal such as magnesium fluoride (MgF) or a mixed crystal thereof, or

 2

 It is selected from optical materials that transmit vacuum ultraviolet light, such as quartz glass doped with a substance such as hydrogen. The transmittance of quartz glass doped with a predetermined substance decreases when the wavelength of the exposure light is shorter than about 150 nm.Therefore, when vacuum ultraviolet light with a wavelength of about 150 nm or less is used as the exposure light, As the optical material, fluoride crystals such as fluorite (calcium fluoride) and magnesium fluoride or a mixed crystal thereof are used.

[0099] In the above embodiment, the exposure apparatus of the step-and-scan method has been described as an example. However, the present invention can be applied to an exposure apparatus of the step-and-repeat method. Further, the present invention is not limited to an exposure apparatus used for manufacturing a semiconductor device. An exposure apparatus used to manufacture displays including display elements (LCDs) and transferring device patterns onto glass plates. An exposure apparatus used to manufacture thin-film magnetic heads and transfers device patterns onto ceramic wafers. It can also be applied to an exposure apparatus used for manufacturing an image sensor such as a CCD and the like.

 In the exposure apparatus to which the above-described liquid immersion method is applied, the substrate P is exposed by filling the optical path space on the light emission side of the optical element 1 at the tip of the projection optical system PL with liquid (pure water). As disclosed in International Publication No. WO 2004Z019128, the optical path space on the entrance side of the optical element 1 of the projection optical system PL may be filled with liquid (pure water).

 In addition, a type of exposure apparatus having no projection optical system, for example, a proximity type exposure apparatus or a two-beam interference type exposure apparatus that exposes a wafer by forming interference fringes on the wafer can be used. .

 Next, an embodiment of a method for manufacturing a micro device using the exposure apparatus according to the embodiment of the present invention in a lithographic process will be described. FIG. 6 is a flowchart showing an example of a manufacturing process of a micro device (a semiconductor chip such as an IC or LSI, a liquid crystal panel, a CCD, a thin-film magnetic head, a micromachine, etc.). As shown in FIG. 6, first, in step S10 (design step), a function and performance design of a micro device (for example, a circuit design of a semiconductor device) is performed, and a pattern design for realizing the function is performed. Subsequently, in step S11 (mask manufacturing step), a mask (reticle) on which the designed circuit pattern is formed is manufactured. On the other hand, in step S12 (wafer manufacturing step), a wafer is manufactured using a material such as silicon.

Next, in step S13 (wafer processing step), using the mask and wafer prepared in step S10—step S12, an actual A circuit or the like is formed. Next, in step S14 (device assembly step), device assembly is performed using the wafer processed in step S13. This step S14 includes processes such as a dicing process, a bonding process, and a packaging process (chip encapsulation) as necessary. Finally, in step S15 (inspection step), inspections such as an operation confirmation test and a durability test of the microdevice manufactured in step S14 are performed. After these steps, the microdevice is completed and shipped. FIG. 7 is a diagram showing an example of a detailed flow of step S13 in FIG. 6 in the case of a semiconductor device. In FIG. 7, in step S21 (oxidation step), the surface of the wafer is oxidized. In step S22 (CVD step), an insulating film is formed on the wafer surface. In step S23 (electrode formation step), electrodes are formed on the wafer by vapor deposition. In step S24 (ion implantation step), ions are implanted into the ueno. Each of the above-described steps S21 to S24 constitutes a pre-processing step in each stage of wafer processing, and is selected and executed according to a necessary process in each stage.

 [0103] In each stage of the wafer process, when the above-described pre-processing step is completed, the post-processing step is executed as follows. In this post-processing step, first, in step S25 (resist forming step), a photosensitive agent is applied to the wafer. Subsequently, in step S26 (exposure step), the circuit pattern of the mask is transferred onto the wafer by the lithography system (exposure apparatus) and the exposure method described above. Next, in step S27 (development step), the exposed wafer is developed, and in step S28 (etching step), the exposed members other than the portion where the resist remains are removed by etching. Then, in step S29 (resist removing step), the unnecessary resist after the etching is removed. By repeating these pre-processing and post-processing steps, multiple circuit patterns are formed on the wafer.

Claims

The scope of the claims  [1] In an exposure apparatus that exposes a substrate via a projection optical system and a liquid,  A liquid recovery device that recovers the liquid supplied to the image plane side of the projection optical system to a recovery unit through a recovery port,  A control device that controls a discharge operation of the liquid collected by the collection unit from the collection unit in synchronization with an operation of the exposure apparatus.  An exposure apparatus comprising:  2. The exposure apparatus according to claim 1, wherein the control device controls the discharge of the liquid from the collection unit when the substrate is exposed to light.  [3] a measurement device for measuring position information of a mark formed on the substrate,  3. The exposure apparatus according to claim 1, wherein the control device performs control for discharging the liquid from the collection unit when the measurement of the mark by the measurement device is not performed. 4.  4. The exposure apparatus according to claim 1, wherein the control device performs control for discharging the liquid in the collecting portion while the substrate is being replaced. [5] A plurality of the collecting units are provided,  2. The exposure apparatus according to claim 1, wherein the control device controls the switching of the collection unit connected to the collection port in synchronization with an operation of the exposure apparatus. 6. The exposure apparatus according to claim 5, wherein the control device performs control for discharging the liquid collected in a collection unit not connected to the collection port. [7] The control device may be configured to terminate the exposure processing of the substrate, to terminate the exposure processing of the substrate in units of a plurality of substrates, or to terminate the exposure processing of a plurality of divided areas set on the substrate. 6. The exposure apparatus according to claim 5, wherein control is performed to switch a collection unit connected to the collection port each time the collection unit is operated. [8] In an exposure apparatus that exposes a substrate via a projection optical system and a liquid,  A liquid recovery device that recovers the liquid supplied to the image plane side of the projection optical system to a recovery unit through a recovery port, A control device for controlling the operation of the liquid recovery device, The liquid recovery device has a plurality of recovery units,  An exposure apparatus, wherein the control device controls switching of a collection unit connected to the collection port.  9. The exposure apparatus according to claim 8, wherein the control device is connected to the collection port, and discharges the liquid collected from the collection unit.  [10] In an exposure apparatus that exposes a substrate via a projection optical system and a liquid,  A liquid supply device for supplying liquid to the image plane side of the projection optical system,  A liquid recovery device that recovers the liquid supplied to the image plane side of the projection optical system to a recovery unit, and a liquid level detection system that detects a surface position of the liquid recovered by the recovery unit,  A control device for controlling liquid supply from the liquid supply device based on a detection result of the liquid level detection system; and  An exposure apparatus comprising: 11. The control device according to claim 10, wherein the control device stops the liquid supply from the liquid supply device when the surface position of the liquid collected by the collection unit reaches the first position. Exposure equipment.  [12] The first position is set so that the liquid supplied to the image plane side of the projection optical system can be recovered by the recovery unit after the liquid supply is stopped. The exposure apparatus according to claim 11, characterized in that: 13. The exposure apparatus according to claim 11, wherein the control device issues a warning when the surface position of the liquid collected by the collection unit reaches a second position lower than the first position. Place.  [14] The control device may be configured such that the surface position of the liquid collected by the collecting unit is lower than the first position, and is maintained between the second position and the second position and the third position. 12. The exposure apparatus according to claim 11, wherein the liquid collected in the collection unit is discharged. [15] The control device may stop discharging the liquid from the recovery unit when the surface position of the liquid recovered by the recovery unit reaches a fourth position lower than the third position. The exposure apparatus according to claim 14, wherein: [16] The apparatus further comprises a substrate stage that holds the substrate and is movable on an image plane side of the projection optical system, wherein the control device is configured to determine that a surface position of the liquid collected by the collection unit is the first position The exposure apparatus according to claim 10, wherein the substrate stage is stopped when the position is reached.  [17] A device manufacturing method using the exposure apparatus according to any one of claims 1, 8, and 10. [18] A liquid processing method in an exposure apparatus that exposes a substrate via a liquid,  A collection step of collecting the supplied liquid in a collection unit;  A discharge step of discharging the liquid collected in the collection unit from the collection unit in synchronization with the operation of the exposure apparatus.  A liquid processing method comprising: [19] The substrate is exposed through a liquid supplied to an image plane side of a projection optical system. 8. The liquid treatment method according to 8. [20] A liquid treatment method in an exposure apparatus that exposes a substrate via a liquid,  A first recovery step of connecting a recovery port for recovering the supplied liquid and the first recovery unit, and recovering the supplied liquid to the first recovery unit;  A second recovery step of connecting the recovery port and a second recovery unit different from the first recovery unit, and recovering the supplied liquid to the second recovery unit;  Discharging the liquid collected in the first recovery unit from the first recovery unit in connection with the recovery port. 21. The liquid processing method according to claim 20, wherein the substrate is exposed through a liquid supplied to an image plane side of a projection optical system.  [22] A liquid processing method in an exposure apparatus that exposes a substrate via a liquid, comprising: a supply step of supplying a liquid onto the substrate;  A collecting step of collecting the liquid supplied on the substrate to a collecting unit,  A stopping step of stopping the supply of the liquid when the surface of the liquid collected by the collecting section reaches a predetermined position; A liquid processing method comprising: 23. The liquid processing method according to claim 22, wherein the substrate is exposed through a liquid supplied to an image plane side of a projection optical system.  [24] An exposure method for exposing a substrate using the liquid processing method according to any one of claims 18, 20, and 22.